L14: Class Amphibia Flashcards
Contrast challenges associated with living in aquatic versus terrestrial habitats Identify anatomical and physiological features that differ in aquatic and terrestrial animals Why is Tiktaalik such a significant paleontological discovery? Contrast circulatory systems of bony fishes versus amphibians Describe threats to amphibian populations
Compare and contrast three challenges in aquatic vs terrestrial environments
Bouyancy - terrestrial have to expend energy counteracting gravity
Respiratory function - Water has low [O2], air has high
Water/salt regulation - Terrestrial environments favour evaporative water loss
What are the three lineages of Sarcopterygii?
Lungfishes
Coelacanths
Tetrapodomorphs
State the skeletal/Muscular elements that aided in the water to land transition
Strengthed axial skeleton (skull and spine, ribs) to support body weight against gravity
Limb reorganization (one bone, two bones, digit bones)
Flexible neck (for up and down movement)
Lighter skull
Increased limb muscles over body wall muscles
What are the three amphibian orders?
Gymnophiona (Caecilians)
Caudata (Salamanders)
Anura (Frogs/toads)
Describe Gymnophiona
Legless
Burrowers
Live in tropical areas
Eyes covered by skin (blind)
Lawvae retained in oviduct and emerge after metamorphosis
Describe Caudata
Retain tail throughout lfe
Aquatic larvae
Internal fertilization without copulation
Spermatophores
Some lungless
What is a spermatophore
Males release sperm into environment
Females come across it, pick it up and store it until she lays eggs and uses it on her eggs
Describe Anura
Adults lack tails
Strong hindlimbs
Inhabit mostly moist habitats
Describe amphibian digestion
Adults are opportunistic carnivores
Juveniles are omnivores
Muscular tongue with mucus glands to make it sticky
Pedicellate teeth (inward flexibility)
Describe amphibian gas exchange
Simple lungs
Lungs supplemented with gills and cutaneous respiration (respiration through the skin)
Air enters the nostril, the floor of hthe mouth drops; raising the floor of the mouth pushes the air into the lungs. Same for exhaling
Describe anuran fertilization
External, larval form
male fertilizes her eggs as she releases them
Larvae go through metamorphosis
Some species have direct development or are paedomorphic
Paedomorphic = retain juvenile features as adult
What are the three parts of the amphibian tripartite brain
Forebrain, midbrain, hindbrain
T/F Amphibians use the lateral line system
True-ish. Aquatic juveniles do
Why are amphibians endangered?
Habitat loss, disease, pollutants, climate change
